Research activities
The IBPPM collection of nonpathogenic microorganisms has 269 newly isolated and culture collection strains of soil and plant-associated (including rhizospheric) bacteria isolated from “clean” and human-polluted regions. These strains have been taxonomically analyzed on the basis of their pheno- and genotypic properties.

The basis of the IBPPM collection is formed by members of the genus Azospirillum, including 124 strains isolated in the Saratov region, 7 type strains (A. amazonense Am14, A. brasilense Sp7, A. doebereinerae GSF71, A. irakense KBC1, A. lipoferum ATCC29707, A. picis TAR-3, and A. thiophilum Bv-S), and 12 strains from other collections. Taxonomic analyses of 38 Saratov Azospirillum cultures have been performed by morphological, cultural, physiological, biochemical, chemotaxonomic and molecular genetic (DNA base composition, DNA–DNA hybridization) methods, and their affiliation with the species A. brasilense and A. lipoferum has been established. A significant part of the IBPPM collection is made up of strains degradative toward hydrocarbons (34 strains) and synthetic surfactants (8 strains); 10 strains are resistant to heavy metals, 10 to arsenic, and 10 to glyphosate.

A study has been made of the immunochemical properties of the surface antigens from 60 strains belonging to the species A. amazonense, A. brasilense, A. doebereinerae, A. irakense, A. lipoferum, A. picis, and A. thiophillum. Antibodies were generated to the lipopolysaccharides (О antigens) of 15 strains of various species, and genus-specific antibodies were developed to the Azospirillum conservative protein antigens.

The IBPPM collection database has been enlarged with
  • information on 37 genera, 52 species, and 269 strains of soil and plant-associated bacteria (including 181 rhizosphere strains); on the properties of 154 strains; and on 15 culture media
  • 111 references
  • information on 175 isolation sites from different regions of Russia, Belgium, Brazil, Ecuador, India, Iraq, Germany, Japan, Lithuania, New Zealand, Pakistan, Portugal, Tajikistan, Taiwan, the UK, and the USA; on 16 isolation substrates; and on 64 microbial culture collections and related organizations.

The database is regularly supplemented with new data derived from the collection staff’s own research on the collection strains (their taxonomic status, morphological–physiological–biochemical characteristics, genetic peculiarities, biotechnological abilities, and current research methods), as well as with relevant references to work published by the collection staff and other investigators. The IBPPM collection database allows evaluation of the state of knowledge on each strain maintained in the collection.

Single strain passports for 124 regional and 7 type strains of Azospirillum have been created and formalized according to the provisional standards worked out under the BRIO project. In addition, single strain passports for 18 hydrocarbon degraders and 8 surfactant degraders have been created.

Phenotypic and genetic descriptions of 12 Azospirillum strains isolated in the Saratov region have been supplemented with data obtained by 16S rRNA gene analysis. As a result, the taxonomic position of six A. brasilense strains has been confirmed. Five other strains, not identified at the species level, were previously assigned to A. brasilense (three strains) and A. oryzae (two strains). Finally, one strain is probably a member of a novel species within the genus Azospirillum.

Among the plant-associated bacteria maintained in the IBPPM collection, direct evidence for ability to promote plant growth has been obtained for 10 strains of the genera Alcaligenes, Azospirillum, Comamonas, Enterobacter, Moraxella, and Pseudomonas. The plant species tested were as follows: in the case of Azospirillum inoculation, Triticum aestivum (cv. Saratovskaya 29), Lolium perenne, and Sorghum bicolor; in all other cases, Sorghum saсcharatum, Sorghum technicum L., and Helianthus annuus L. However, more than 40 strains can be considered to be potential biofertilizers, because they have one or several plant-growth-promoting traits. Among these strains are (i) 15 producers of the phytohormone indole-3-acetic acid (IAA), which can synthesize 1.3–44.7 μg mL-1 IAA during stationary growth (HPLC data); (ii) 4 inorganic phosphate solubilizers, detected in a plate test by the formation of Ca3(PO4)2 clearing zones around the colonies; and (iii) 32 nitrogen fixers, whose acetylene reduction activity ranges from 24 to 1269 nmol ethylene h-1 (mg dry weight)-1.

The group of the plant-associated bacteria able to degrade various man-made pollutants includes 34 taxonomically different strains. Degradative activity toward crude oil (20 to 65% for 14 days) has been shown for 16 strains of the genera Azospirillum, Brevundimonas, and Pseudomonas by determining the residual oil concentration in the culture medium. Degradative activity toward diesel oil (20 to 45% for 5 days) has been found for 8 strains of the genera Arthrobacter, Bacillus, Mycobacterium, Pseudomonas, and Rhodococcus by gas–liquid chromatography by determining the total residual concentration of the С11–С21 hydrocarbons in the culture medium. Degradative activity toward polycyclic aromatic hydrocarbons (anthracene, fluorene, naphthalene, and phenanthrene) has been observed by gas–liquid chromatography for 10 strains assigned to the genera Acidovorax, Arthrobacter, Mycobacterium, Pimelobacter, Pseudomonas, and Sinorhizobium. In particular, the phenanthrene-degrading activity of these bacteria can be in the range 20–99% for 5 days of culturing. Moreover, these degraders of polycyclic aromatic hydrocarbons have been screened for the presence of the phnJ gene, encoding the key catalytic component of the C–P lyase multienzyme system, which is used by bacteria to utilize phosphonates. The presence of the phnJ gene has been analyzed by PCR amplification by using a set of degenerative primers. These primers were designed on the basis of conserved motifs present in the 86 phnJ sequences available in the NCBI database and were tested successfully with phnJ-containing strains of the bacteria Agrobacterium tumefaciens C58 (AE007869), Cupriavidus metallidurans CH34 (CP000352), Escherichia coli K-12 (U14003), and Sinorhizobium meliloti 1021 (NC 003078). The presence of the phnJ gene has been found in five polycyclic aromatic hydrocarbon-degrading strains of the genera Arthrobacter, Pimelobacter, and Sinorhizobium, which was confirmed by analysis of the PCR-product sequences.
Staff members
  • Professor Olga Turkovskaya, D. Sc. (Biol.), Head of Collection
  • Ekaterina Dubrovskaya, Ph.D. (Biol.), Curator
  • Anna Muratova, D. Sc. (Biol.), Bacteriologist
  • Sergey Golubev, Ph.D. (Biol.), Bacteriologist
  • Anastasia Bondarenkova, Ph.D. (Biol.), Bacteriologist